Yuzhen Cao | Search PubMed

PubMed2006

[Evaluation of back muscle function based on EMG time-frequency spectrogram analysis].

EMG has been extensively used to study function of back muscle, which plays an important role in the objective assessment of occupational low back pain, yet the inherent large variability of EMG signals across subjects produced by reasons already known or unknown may mask true biological differences. Some useful parameters abstracted from 8-channel EMG signal in time-frequency domain are used or proposed and calculated in this paper to decrease this variability, when comparing the possible difference between low back pain patients and normal control group. The calculation of instantaneous median frequency is improved to decrease the interruption of background noise, and different power densities in EMG time-frequency spectrogram are observed in two tested groups.

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PubMed2005

[Application of independent component analysis to ECG cancellation in surface electromyography measurement].

Surface electromyogram usually incurs severe influence of strong electrocardiography (ECG) signal. This paper presents a novel denoise method using independent component analysis (ICA) to remove the interference of ECG from sEMG recordings. The present study removed the ECG in independent components decomposed from the sEMG by a high-pass filter that kept the useful information as more as possible during ECG cancellation. The filtering ICA ECG cancellation results were compared with the simulated pure sEMG in time and frequency domain, which suggested that the ICA ECG cancellation with 30Hz high-pass filter would be the most appropriate method to extract the useful sEMG signals from multi-channel sEMG measurement. The kurtosis is used to measure the nongaussianity of signal; it may beused as a standand for automatic determination of the independents of ECG or EMG.

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